Indeed, although ab overexpressing clones alone did not upregulate msn-lacZ expression (Figure 8A,B), the reporter was strongly activated within scrib−+ab tumours, most notably within basal portions of the tumour and in cells that appeared to be migrating between the brain lobes, consistent with a role for JNK in promoting invasion (Figure 8C,D). Here, MAPK8 is linked to neoplasm.